As mobile computing devices, such as smartphones and tablet computers, continue to proliferate, they are rapidly becoming the platform of choice for users who access online applications. However, the process of interacting with a mobile application can be challenging because mobile applications typically have a much smaller amount of screen real estate to work with than desktop applications, which makes it hard to display a large number of application control elements, such as buttons or sliders, to a user.
Moreover, users typically interact with these control elements by using a finger to tap or swipe associated regions on a touchscreen. However, a user's finger is a relatively blunt instrument in comparison to a cursor in a desktop user interface (UI). Hence, the targets for touchscreen taps or swipes need to be larger than corresponding targets for cursor selections in a desktop UI. This means that fewer control elements can be presented through a mobile application UI, because each control element takes up more screen real estate than a similar control element in a desktop UI.
The designer of a mobile UI needs to carefully size the “tap targets” for control elements. If a tap target is too small, a user who attempts to activate the tap target is likely to fail, which requires the user to try again and thereby degrades the user's experience. On the other hand, if the tap target is too large, the user may inadvertently activate the tap target, which also leads to an unsatisfactory user experience.
Hence, what is needed is a mechanism that helps a UI designer to determine the optimal size for a tap target.